Week 1 - F(2) - Microbiology Practical Tutorial (Labs) Flashcards
- A 28 year old man attends the Sexual Health clinic complaining of pain when he passes urine and a purulent urethral discharge. What do you think the diagnosis may be already?
Neisseria gonorrhea
You take a urethral swab for microscopy (done at the clinic) and bacterial culture and a “first pass” urine for combined chlamydia and gonococcal PCR . You are provided with a Gram stained film of the urethral discharge made in SRH clinic What does the gram stain show?
The gram stain shows a gram negative intracellular diplococci
(b) What diagnosis does this Gram film result suggest? (c) What treatment would you give this patient for this infection?
Diagnosis suggestive of Neisseria Gonorrhea Give this patient IM ceftriaxone + Oral azithromycin
Why is the oral azithromycin given?
Oral azithromycin co-treats the gonorrhea and helps to prevent resistance against ceftriaxone emerging Oral azithromycin is also protective against a potenital chalmydia infection
d) Gonorrhoea (and Chlamydia) are diagnosed these days primarily by PCR (NAATs) testing. What are the advantages of using this type of test instead of culture?
The NAAT testing is much quicker (takes hours instead of days) It is highly specific and sensitive to the organisms The test can test organisms that have died and therefore does not need to be carried out in the SRH clinic The test also requires a less invasive swab to be taken
(e) What is the main disadvantage of using PCR testing for gonorrhoea?
The test cannot test antibiotic sensitivities as unable to culture Also cannot test of cure for organisms until after 5 weeks as the test will detect dead organisms
(f) Patients attending the Sexual Health clinic are offered tests for a range of sexually transmitted infections. What other infections do you think the clinic would test for in this patient? (g) The patient is given an appointment to return to the Sexual Health clinic 12 weeks after the date of his visit to Amsterdam. Why?
Test for chlamyida, gonorrhea, HIV, Hep B, Syphilis 12 weeks post amsterdam will be able to test for HIV
Case 2 A 19 year old woman attends your GP surgery complaining of vaginal discharge and intense vulval itch which she finds very uncomfortable.. You take a high vaginal swab for culture and the organism shown (Gram film and culture) is isolated. What is this?
This is organism is candida (albicans) can see the hyphae and budding of the yeast organism
She had unprotected sex 2 weeks earlier at a party with a new partner, but she is taking oral contraceptives. She is worried that she may have picked up some sexually transmitted disease from her new boyfriend. On examination, the vulva is very red and inflamed and there is a thick white discharge What is the casual organism and what is the treatment?
The casual organism of the vaginal candidiasis is candida albicans Treatment would be to give the patient Oral fluconazole + clotrimazole cream Clotrimazole pessary + clotrimazole cream
d) Should her boyfriend be treated too? (e) What other advice do you give her?
Boydirend should only be treated if he has symptoms as candida most commonly is not sexually transmitted Candidia reinfections are common
(f) What specimen would you (the GP) also have been taken from this patient to check for chlamydia and gonorrhoea and why would you ask her for a contact telephone number?
The GP would have taken a swab for NAAT testing (not for culture as the SRH clincs carry out culture as the organisms need to be tested immediately) Get telepjone number in case you have to call the patient to tell her off the results
Case 3 A 26 year old lady attends the gynaecology clinic complaining of a yellowish vaginal discharge. A HVS is taken and submitted to the laboratory. The laboratory sees the organism shown moving about on microscopy. (a) Describe what you see.
Can see a protozaoal infection - the flagellae is there to help with movement of the protozoal infection
(b) What is this organism seen on microscopy? (c) How has the patient acquired this infection?
The organism is trichomoniasis vaginalis Patient has acquired the infection via sexual transmission
Why is the organism shown on microscopy not bacterial vaginalis? (which organism cause bacterial vaginalis) How is bacterial vaginalis transmitted?
Bacterial vaginalis is caused by gardnerella vaginalis This is a gram variable staining bacteria It is not transmitted and instead is due to a change in the normal vaginal flora
(d) What treatment would you give to treat the trichomoniasis vaginalis? This also treats bacterial vaginosis (e)Should her partner(s) be treated too?
Would give oral metronidazole The patients partner should be treated too
Case 4 - A 28 year old woman visits her GP.. She has had several attacks of a similar nature in the past two years. The lesions start as small blisters, i.e. vesicles and then become pustular. They are exquisitely painful and the vulva is inflamed: she also has difficulty passing urine. The attacks last about two weeks and then resolve. The patient is sexually active and her general health is good. What is the diagnosis of the patient? What are the clssical symptoms?
This patient has genital herpes Several attacks, difficulty passing urine, starts as blisters before ulceration
(b) What is the likely infectious agent? (c) What specimen would you take to confirm the diagnosis?
Likely infectious agent would be HSV-1 or HSV-2 Would deroof a blister and take a swab and send on viral transport medium for PCR testing
(d) Why is it important to confirm the diagnosis? (e) Name one antiviral therapy available for this condition.
This condition is highly transmissible and therefore important to confirm diagnosis - can also badly affect the immunocompromised One antiviral therapy for this is acicylovir
What is the most common viral STI in the UK?
Most common viral STI would be human papilloma virus
Case 5 A 35 year old man has developed these lesions over a period of about 18 months. His girlfriend insisted he see a doctor because she “won’t have sex with a cauliflower”. An illustration of the condition is provided. (a) What are the lesions?
These are genital warts
Are the lesions in genital warts usually painful?
The lesions are not particularly painful or tender Can be tender when wearing tight underpants and the skin becomes chafed.
(b) Which virus causes genital warts?
Human papilloma virus causes genital warts HPV types 1-4 warts/verucas HPV types 6&11 causes genital warts HPV types 16&18 causes cervical cancer
(c) Will sending a swab of the lesions for viral culture help to confirm the diagnosis? (d) Is the girl just fussy or does she have reason to worry about herself?
Sending a swab wil help yes The girl has a right to worry as HPV is a major cause of cervical cancer
What treatment is available for the HPV lesions on the mans penis? Which treatment can be used on all anogenital warts for HPV?
Podophyllotoxin (warticon) - this is a cytotoxic therapy Inquimodi is also an availabe treatment - inquimoid can be used on all anogenital warts Cryotherapy is also a treatment - may require repeat treatments
